Improvement in pistons



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Letters Patent No. 108,682, dated October 25, 1870.

IMPROVEMENT IN PISTONS.

The Schedule referred to in these Letters Patent and making part of thesame.

I, ISAIAH DAVIS BUCK, of Conshohocken, county of Montgomery, State ofPennsylvania, have inventedA an Improved Piston, of whichthe'followingis a. specification. i

Nature and Object of the Invention.

My invention consists principally in the employment of tapering keys orwedges for expanding the packingv rings of pistons; also in certainimprovements, fully described hereafter, in the construction of pistons.

Description of the Accompanying Drawing. Figure 1 is a sectional view ofmy improved piston;

Figure 2, an end view of the same with the follower removed; Figure 3,represents the several parts of the piston detached from each other;

Figure et is a side view, partly in section; and Figure 5, a view of oneof the wedges for expanding the piston.

General Description..

The body of the piston consists of a head or stock, A, which, in thepresent instance, is cast in one piece with the piston-rod B.

This stock is cnt away for the reception of the split packing-rings0,1), and D', which are retained between the ange a of the stock, and adisk or follower, F, which is secured to the end ofthe piston by boltsor screws b, and which has a central enlargement or projection, c,adapted to a recess in the stock, as best observed in iig. l.

This latter arrangement serves to adjust the followcrto a centralposition, and to relieve the strain upon the bolts or screws b.

For the purpose of expanding the packing-rings I employ tapering keys orwedges H, which, in the pres- 'en-tzinsta-ncc, are five in number,and'are adapted to the recesses i, formed in the stock Abeneath the saidpacking-rings. The 'stock is also cnt away, at It, to a depthcorresponding to that of the recesses i, in order 'that the ends of thewedges may project from the said recesses. This enables the'wedges,which are notched at in, to beseized by tongs X, or other suitableinstrument, and withdrawn from their recesses after removing thefollower F. v

In order to facilitate the introduction and withdrawal of the wedges,the latter might be tapered on all four sides, instead of upon two sidesonly, as shown in the drawing.

After the wedges have been driven in to their full extent, and itbecomes necessary to still further expand the rings, thin strips ofmetal p may be in serted beneath the wedges, as shown in tig. 4. A

It'will be observed, on reference to tlg. 3, that the opposite endsofthe split ring G are tapered, so as to form a wedge-shapedspace-between them. This enables a wedge to be driveninto the saidspace, after the piston has been tted to the cylinder, for the purposeof determiningt the extent of the expansion of the rings.

If the expansion has been too great, the ring will not yield tothewedge, while, if itv is not great enough, the wedge will readily enter.This forms a ready test for the proper adjustment of the wedges H.

It will be seen that, after the plate F has been'secured to its place,bearing against the end ofthe head A, the wedges H will be confinedbetween thefol-A lower and rim a., and will be incapable of furthermotion, so that the piston is solid throughout, without loose parts, orparts which can become loose, and permit the unequal wear of the rings.

Claims.

1. The stock A, its flange c, and recesses yi, in combination with thefollower' F, fitting against the head of the stock, the rings C D D',and wedges H, immovably confined between the follower and flange a,

as and for the purpose described.

2. The said stock, recessed at i, in combination with the said wedges,recessed near their outer ends, as

and for the purpose specified.

In' testimony whereof, I have signed my name to this specification inthe presence of two subscribing

